To answer my own question:
1. Gin can be used to inject the EventBus into the View as well as the
Presenter, so now our View has a reference to the EventBus
2. In order to give the EventBus to the Widgets "owned" by the View
those Widgets will require a constructor argument which will be the
EventBus instance. UiBinder will fail if it doesn't find a default
constructor, except that they have provided some nice work arounds.
The appropriate workaround in this case is to provide a widget
factory. Notice the use of @UiFactory in the example below:
public class UserDashboard extends Composite {
interface MyUiBinder extends UiBinder<Widget, UserDashboard>;
private static final MyUiBinder uiBinder =
GWT.create(MyUiBinder.class);
private final String[] teamNames;
public UserDashboard(String... teamNames) {
this.teamNames = teamNames;
initWidget(uiBinder.createAndBindUi(this));
}
/** Used by MyUiBinder to instantiate CricketScores */
@UiFactory CricketScores makeCricketScores() { // method name is
insignificant
return new CricketScores(teamNames);
}
}
On Jun 23, 11:04 pm, Paul Schwarz <paulsschw...@gmail.com> wrote:
> Working with the MVP pattern, or more like the VP pattern at this
> point, I have:
> MainPagePresenter
> MainPageView
> WidgetA
> WidgetB
>
> ... so imagine that WidgetA and WidgetB will be attached to
> MainPageView.
>
> Using Gin I have an EventBus injected into the MainPagePresenter. I
> can then add click handlers that place an event on the EventBus from
> within my MainPagePresenter. This might look like:
>
> getMainPageView().getSendButton().addClickHandler(new ClickHandler(){
> public void onClick(ClickEvent event) {
> eventBus.fireEvent(new SendEvent());
> }
>
> }
>
> But now let's say that WidgetA and WidgetB actually have quite a few
> user interactions, you'll end up with a lot of methods that look like
> the one above sitting in your Presenter class.
> 1. Is this correct?
> Or
> 2. should the Presenter hand the reference to the EventBus through to
> its View, who may even hand it through to the Widgets so that they can
> talk directly to the EventBus?
>
> If the second option is the better option from an architecture/
> separation of concerns point of view, then what is the best way to
> hand the reference over to the View in such a way that keeps the
> coupling between Presenter and View as loose as possible?
>
> Note, currently my Presenter defines a View interface which my View
> implements, so the coupling is loose but based upon this interface.
--
You received this message because you are subscribed to the Google Groups
"Google Web Toolkit" group.
To post to this group, send email to google-web-tool...@googlegroups.com.
To unsubscribe from this group, send email to
google-web-toolkit+unsubscr...@googlegroups.com.
For more options, visit this group at
http://groups.google.com/group/google-web-toolkit?hl=en.
